[The dynamics of the structural reconstruction of mitotic chromosomes after their artificial decondensation in vitro].
The treatment of isolated metaphase chromosomes with 5 mM Tris buffer caused their decondensation into DNP fibers 10 nm in diameter. The following increase in CaCl2 concentration induced the transition of nucleosomic DNP fibers into DNP fibers 20 nM and 40-50 nM in diameter, and the recovery of the whole chromosomes. However, in the similar conditions, the typical chromosomes (threads about 100 nm thick), chromomeres and G-bands were not reconstructed. According to these data, we assume that DNP threads 40-50 nm in diameter may be artificial (i.e. "pseudochromonemes"). The treatment of isolated chromosomes with 0.35 and 0.6 M NaCl prevents from formation of nucleomeric and pseudochromomeric fibers, although bodies of chromosomes can be recovered after the removal of HMG and H1 proteins. These observations point to a high stability of chromosomal fasteners providing the structural integrity of mitotic chromosomes.
Kireev
I I
II
Zatsepina
O V
OV
Poliakov
V Iu
VIu
Chentsov
Iu S
IuS
D000818:Animals; D002122:Calcium Chloride / Q000494:pharmacology; D002478:Cells, Cultured / Q000187:drug effects / Q000648:ultrastructure; D002871:Chromosome Banding / Q000379:methods; D002875:Chromosomes / Q000187:drug effects / Q000648:ultrastructure*; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000187:drug effects / Q000648:ultrastructure; D015636:Magnesium Chloride / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D008938:Mitosis / Q000187:drug effects; D014325:Tromethamine / Q000494:pharmacology
D014325:Tromethamine; D015636:Magnesium Chloride; D004247:DNA; D002122:Calcium Chloride
Dinamika strukturnoĭ rekonstruktsii mitoticheskikh khromosom posle ikh iskusstvennoĭ dekondensatsii in vitro.